1. Field
The present application relates to a camera module, and in particular to a camera module which is generally installed at a mobile terminal.
2. Background
In recent years, a variety of mobile terminals are widely used, and faster wireless internet services become available. The customers of such mobile terminals are demanding various advanced functions. To meet such demands, a variety of value-added devices are increasingly installed at the mobile terminals. Among such value-added devices, there is a camera module configured to photograph a predetermined object in a form of photo or motion picture and store such an image data and edit and transmit based on the necessity of a user.
The compact-sized camera module is increasingly used at a variety of multimedia devices such as a note pad type personal computer, a camera phone, a PDA, a smart toy, etc. and is also used at an image input device such as an information terminal of a monitoring camera or a video tape recorder. As the pixel sizes of the sensor applied to the camera module decrease and the height of the module lowers, a camera module with a new mounting structure has become a serious issue, which aims to secure high durability in the mechanical components of the camera module, more specifically, in a tilt or shift-related component of a lens optic axis along with a good management against the input of impurities.
In the related camera module, the engagement of a cover can encasing a lens barrel and an actuator unit and a base disposed to install an IR filter on a printed circuit board (PCB) is implemented by an engaging protrusion which protrudes from a lower side surface of the cover can and an engaging groove formed at an upper side surface of the base and corresponding to the engaging protrusion. In such an engaging structure, the manufactured camera module may have a slight allowance due to the formations of the engaging groove of the base and the engaging protrusion of the cover can. The above-described engaging method wherein such an allowance occurs may not be proper for the use at the camera module which requires good optic axis alignment.
In order to possibly solve such a problem, the cover can and the base may be fixed using an adhesive. Since a relatively smaller area between the cover can and the base is fixed using an adhesive, the adhesive flowing out from the cover can needs to be eliminated, causing increased time and cost in terms of product productivity.
For the adhesive, a thermosetting adhesive which hardens by heat and a UV-hardened adhesive which hardens by UV may be used. In case that the thermosetting adhesive is used, the camera module is thermally treated in the oven. A predetermined material and component which are denaturized by means of heat during the above-mentioned heat treatment should be used, which causes increased cost. When the UV-hardened adhesive is used, it is difficult to properly scan for hardening the adhesive due to the compact size of the camera module and a portion where the adhesive is applied is too small. Such a problem related to the scanning of UV also occurs when performing a main adhering procedure using a thermosetting adhesive after a temporal adhering is performed using the UV-hardened adhesive.
If the adhesive flows inside of the cover can, the adhesive may contaminate other inside components such as an IR filter causing problems with the reliability and quality of products. Such a problem may occur when the fixing force by the adhesive is not enough, and the adhesive may be peeled off due to external impacts, resulting in poor durability of the product.